Add Eloverblik data pipeline: fetch metering points, readings, and charges to PostgreSQL

- Add eloverblik controller with API client for metering points, time series, and charges
- Add migrations for metering_points, meter_readings, and charges tables
- Add HugSQL queries (upsert-metering-point!, insert-meter-reading!, insert-charge!)
- Add POST /eloverblik/sync route to trigger sync from browser

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

resources/migrations/20260214140000-create-metering-points.up.sql

@@ -0,0 +1,15 @@
+CREATE TABLE metering_points (
+  metering_point_id  VARCHAR(18)  PRIMARY KEY,
+  type_of_mp         VARCHAR(50),
+  balance_supplier   VARCHAR(100),
+  street_name        VARCHAR(200),
+  building_number    VARCHAR(20),
+  postcode           VARCHAR(10),
+  city_name          VARCHAR(100),
+  has_relation       BOOLEAN,
+  settlement_method  VARCHAR(50),
+  reading_occurrence VARCHAR(50),
+  consumer_start_date DATE,
+  first_consumer_name VARCHAR(200),
+  fetched_at         TIMESTAMPTZ NOT NULL DEFAULT now()
+);